Space heating stove with air circulating jacket



Nov. 8, 1949 H. F. NELSON I 2,487,264

SPACE HEATING STOVE WITH AIR CIRCULATING JACKET Filed Feb. 21/1948 ,uu nn nn."a"

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HENRY FNELSON,

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Patented Nov. 8, 1949 SPACE HEATING STOVE WITH AIR CIRCULATING JACKET Henry F. Nelson, Danville, Ill. Application February 21, 1948, Serial No. 10,138

1 Claim.

This invention relates to convection heaters, particularly of the natural draft type, and its overall objective is to provide a safe, efficient heater of simple, inexpensive and long-lasting construction.

One of the specific objects of this invention is to provide a heater having a draft control construction which by retarding the escape of sparks and flames from the combustion chamber into the flue will achieve both the safety result of eliminating one of the prime causes of fires and the efliciency result of reducing one of the major losses of heat connected with conventional heaters.

Another specific object of this invention is to provide a heater having a draft control construction which by preventing excessive drafts and promoting complete combustion of gases will effect a substantial reduction in the amount of heat ordinarily wasted up the flue and a corresponding increase in the amount of heat delivered to effective heating surfaces.

Still another specific object of this invention is to provide a heater having a draft control construction which, without the use of baffies, will cause a long travel of hot gases to distribute a great amount of heat substantially evenly to the walls and top of the combustion chamber thereby achieving an extensive as well as an intensive use of all of the available prime heating surface. This feature of the invention not only prevents the burn-outs caused by the usual heat concentrations on the flue side and top of the combustion chamber but also permits an effective employment of outside convection currents to carry the heat from the increased heating surface into the room so as to obtain the maximum in safety, efiiciency and service from a heater of a given size.

Another object of this invention is to provide a heater having a jacket construction which by controlling the direction of convection currents flowing over and from the heating surfaces of the combustion chamber will assure a quick, steady delivery of an abundance of heated air out the sides as well as from the top of the heater and so achieve an even, efiicient and comfortable warming of the room from floor to ceiling;

Objects and advantages other than those listed above will be apparent to those skilled in the art from the following description when read in conjunction with the accompanying diagrammatic drawing, in which Fig. 1 is a view intop plan with portions broken away; and

Fig. 2, a view in central vertical section on the line 2-2 in Fig. 1.

Construction Referring more particularly to the drawing, in which like characters of reference indicate like parts in both views, reference character 3 designates a base upon which is mounted a cylindrical drum 4 enclosing a combustion space 5. Centrally positioned on the inside bottom of the drum is a burner 6, of any suitable type, which may be easily lighted, inspected and serviced through the passageway of the sleeve 1 when the door 8 at the front of the heater is open.

Located within and near the top of the drum 4 is a pipe 9 which extends horizontally from near the front of the drum centrally through the rear of the drum and out the jacket ID to a flue connection, shown as an elbow ll. Near its front end, which is sealed by the plug l2, the pipe 9 is perforated with a series of gas outlets l3, and it is likewise perforated with a similar series of gas outlets l4 near the rear of but inside the drum 4. The gas outlets l3 are preferably greater in number or size than the gas outlets I 4 so that the intensity of draft will be nearly the same at both points.

The drum 4 is completely enclosed by the sides and top of a rectangular jacket designated generally by the reference character I0. This jacket I0 is spaced apart from the drum 4, and a solid, rectangular member I5, the bottom of which is herein shown in contact with the top of the drum 4 and the ends of which are fastened to the sides of the jacket ID in gas-tight seals, horizontally divides the space within the jacket [0 outside the drum 4 into an upper heating dome l6 and a lower heatin chamber IT. The member I5 is preferably made of a thin sheet of heat conductive metal.

The sidewalls of the jacket l0 below the member I5 are provided with cold air inlets l8 and hot air outlets I 9 in the nature of louvers located respectively near the lower and upper limits of the chamber I1. The sidewalls of the jacket l0 above the member l5 are provided with air inlets 20 in the nature of louvers located near the lower limit of the dome l6, and in the top of the jacket 10 are provided air outlets 2| in the nature of slots.

Operation When the heater is in operation, the flame from the burner 6 heats the air within the combustion space 5 causing that air to expand and so become light. This heated air and also the hot gases of combustion rise within the drum 4 as they are pushed up by colder, heavier air from outside the heater which, at the same time, is constantly being drawn into the combustion space 5 from below. This cold air in turn passes over and through the burner 6, becomes heated, expanded, and lighter, and also rises within the drum 4 as fresh supplies of cold air are drawn into the combustion space 5 to replace the warmer, lighter air and gases which eventually pass from the top of the drum 4 out the gas outlets l3 and I4 to the flue connection ll. Since this action is continuous as long as the heater is in operation, there is created an upward flow of hot air and gases Within the drum 4.

The size and number of the gas outlets l3 and I4 may be readily made to be such as to prevent excessive drafts within the drum 4 and so promote combustion of gases within the combustion space 5.

Sparks and flames from the burner 6 are substantially prevented from escaping from the combustion space 5 into the flue connection H by the solid portions of the horizontal length of pipe 9 located within the drum 4 as well as by size and location of the gas outlets l3 and I4.

Because of the location of the gas outlets I3 and I4, and because the size and number of those gas outlets are such that the intensity of draft is nearly the same at both points, the upward flow of hot air and gases within the combustion space 5 is directed along the walls to the top of the drum 4 from which the air and gases deflect and swirl and eddy around the pipe 9 before finally escaping out to the flue connection II. The walls of the drum 4 are thus heated evenly and efficiently as a consequence of the long travel of hot air and gases which is thus directed over their surface; and the top of the drum 4 likewise becomes heated by the hot air and gases deflected from it. The pipe 9 itself becomes an auxiliary heating surface which is heated by the hot gases and heated air swirling around and through it. After the pipe 9 becomes heated, it radiates additional heat to the top of the drum 4 throughout its length contained in that drum.

As the drum 4 becomes heated, there is set up within the lower heated chamber l1 therearound convection currents of air as cold air drawn in through the air inlets l8 passes over the heated walls of the drum 4, becomes warmed, and rises to the upper limit of the chamber H where it is deflected from the member 15 and flows out the sides of the heater through the air outlets l9 into the room. Since this action is continuous as long as the heater is in operation, a steady delivery of warmed air out the sides of the heater is assured.

The member I5 becomes heated both by the deflection of warmed air rising in the lower heated chamber 11 and by conduction of heat directly from the top of the drum 4 with which it is in direct contact. The member [5 thus not only prevents the convection currents in the lower heating chamber from flowing out through the top of the heater but also acts as the prime heating surface of the upper heating dome IT.

A considerable amount of heat will be transferred to the member l5 through conduction from the top of the drum 4 inasmuch as the top of the drum 4 is heated not only by the deflection of the hot air and gases arising in the combustion space 5 and by their subsequent swirling and eddying about the pipe 9 seeking escape through the gas outlets l3 and I4 but also by radiation of heat from the pipe 9 itself as that pipe becomes an effective auxiliary heating surface which is heated by the hot air and gases swirling around and through it.

As the member [5 becomes heated, the air in the upper heating dome l6 also becomes heated, and it rises and flows out the air outlets 2| located in the top of the jacket I0, and at the same time, it is replaced by other air which is drawn into the dome [6 through the air inlets 20 and which passes over the upper surface of the member I5, becomes heated, and also rises and flows out the air outlets 2|. Since this action is continuous as long as the heater is in operation, there is delivered out of the top of the heater into the room a steady flow of warmed air.

Since I have described my invention in but the one particular form, it is obvious that many structural changes can be made in that form without departing from the spirit of the invention, and I therefore do not desire to be limited to the precise form shown except as may be required by the following claim.

I claim:

In a space heater, a combustion drum; a drum discharge conduit disposed substantially diametrically across and within the upper portion of said drum to lead outside thereof, said conduit having openings circumferentially spaced therearound in two longitudinally spaced apart zones, each of said zones being adjacent opposite sides of said drum; a jacket surrounding and spaced apart from said drum and extending thereabove; a partition member in heat transfer relation to the top of said drum and constructed and arranged to divide the space within said jacket into a lower chamber surrounding said drum, and an upper chamber above said drum; a top member across said jacket; said jacket being provided with two zones of air passage openings, one adjacent the under side of said partition member, and the other near the bottom of said jacket, and said jacket being further provided with air passage openings in its side walls above said partition, and also through said top member.

HENRY F. NELSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 57,481 Conver et al Aug. 28, 1866 345,293 Finch July 13, 1886 1,151,705 Joy Aug. 31, 1915 FOREIGN PATENTS Number Country Date 654,297 Germany Dec. 16, 1937 A, l A 

